Geth: Genesis block mismatch & subprotocol error

Question

I'm using Geth 1.7.3 in MacOS 10.13.2 High Sierra.

When I'm running Geth to sync the main network, the verbose log (verbosity=4) tells there are quite a few errors:

• subprotocol error
• Genesis block mismatch
• block download canceled (requested)
• useless peer
• i/o timeout
• read timeout

The command I use is:

geth --fast --cache=2048 --verbosity=4

To ensure I'm using a correct DB, I remove the old database and create a new account before I run the command above:

geth removedb
geth account new

Why do I receive these errors from remote node? How do I resolve?

p.s. I'm unable to connect to any node for an hour.

Also tried with a different new datadir, same error messages appeared.

Console output:

INFO [01-24|15:18:04] Starting peer-to-peer node               instance=Geth/v1.7.3-stable/darwin-amd64/go1.9.2
INFO [01-24|15:18:04] Allocated cache and file handles         database=/Users/adv/Library/Ethereum/geth/chaindata cache=128 handles=1024
INFO [01-24|15:18:04] Initialised chain configuration          config="{ChainID: 1 Homestead: 1150000 DAO: 1920000 DAOSupport: true EIP150: 2463000 EIP155: 2675000 EIP158: 2675000 Byzantium: 4370000 Engine: ethash}"
INFO [01-24|15:18:04] Disk storage enabled for ethash caches   dir=/Users/adv/Library/Ethereum/geth/ethash count=3
INFO [01-24|15:18:04] Disk storage enabled for ethash DAGs     dir=/Users/adv/.ethash                      count=2
INFO [01-24|15:18:04] Initialising Ethereum protocol           versions="[63 62]" network=1
INFO [01-24|15:18:04] Loaded most recent local header          number=0 hash=d4e567…cb8fa3 td=17179869184
INFO [01-24|15:18:04] Loaded most recent local full block      number=0 hash=d4e567…cb8fa3 td=17179869184
INFO [01-24|15:18:04] Loaded most recent local fast block      number=0 hash=d4e567…cb8fa3 td=17179869184
INFO [01-24|15:18:04] Loaded local transaction journal         transactions=0 dropped=0
INFO [01-24|15:18:04] Regenerated local transaction journal    transactions=0 accounts=0
INFO [01-24|15:18:04] Starting P2P networking 
INFO [01-24|15:18:06] UDP listener up                          self=enode://d121d375590c5d4f98ce9262d98667fa5808578237a11ae79192ed4a4c489010a754f115dffe7e0020677943984504a924e36a02ea86cf2ee25f80f91cbe4cf4@[::]:30303
INFO [01-24|15:18:06] RLPx listener up                         self=enode://d121d375590c5d4f98ce9262d98667fa5808578237a11ae79192ed4a4c489010a754f115dffe7e0020677943984504a924e36a02ea86cf2ee25f80f91cbe4cf4@[::]:30303
INFO [01-24|15:18:06] IPC endpoint opened: /Users/adv/Library/Ethereum/geth.ipc 
INFO [01-24|15:18:36] Block synchronisation started 
WARN [01-24|15:18:44] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:19:48] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:20:03] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:20:23] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:20:43] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:21:10] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:21:28] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:21:37] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:21:54] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:22:00] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:22:30] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:22:43] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:23:38] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:24:05] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:24:15] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:24:48] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:25:30] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:25:50] Synchronisation failed, retrying         err="block download canceled (requested)"
WARN [01-24|15:26:01] Synchronisation failed, retrying         err="block download canceled (requested)"

Answer 1

It seems that many nodes out there on the internet are running in private chains, not on the public chain. And that means they are using a different genesis block. Which makes them incompatible with the public chain.

In my experience it takes a while (maybe 15 minutes) before synchronisation starts because of the relative number of nodes near me (in internet terms) in the UK which are not on the public chain.

It's even worse on the Ropsten test network, I suppose because most testing is in private chains rather than newbies like me wanting the public test chain.